The present invention relates to a device for generating contact pressure of a plasticizing and injection unit nozzle against a mold half, wherein the mold half is provided on a stationary platen. More particularly, the present invention relates to such a device which exhibits compression springs and a spindle drive, wherein the spindle drive is arranged between the stationary platen and the displaceable plasticizing and injection unit.
Devices for generating a nozzle contact pressure are known from European Patent Application No. 0 328 671 A1. The compression springs of this known device are arranged around the individual rods of a rod assembly. The rod assembly is connected to a plate which serves, on the one hand, as one of the spring bearings, and., on the other hand, is connected to a nut of the spindle drive by way of intermediate elements. The spring system is free and is subjected to operational and atmospheric interference. In addition, the rods and the compression springs arranged around the rods are guided through a plate. The spindle passes through the same plate, thus, the plate forms the other spring bearing and is connected stationarily to the plasticizing and injection unit.
The present invention is based on the problem of making the design of the spindle drive and other elements of the device simple. More particularly, the present invention relates to a device wherein compression springs are mounted operationally and to avoid, or minimize, the varying adverse effects on the spring elements.